a) Field of the Invention
The invention is directed to a rear projector with a housing on whose front side is arranged a screen for showing a video picture, with a brightness-modulated and color-modulated R-G-B light source for emitting a light bundle, with a deflecting device for scanning this light bundle, wherein the light bundle is deflected by the deflecting device over a total angle .alpha. with respect to vertical scanning, and with a deflecting mirror which is located in the housing and arranged at an angle .delta., wherein the light bundle exiting from a virtual vertex of the total deflection angle .alpha. is deflected on the screen by the deflecting mirror.
b) Description of the Related Art
Rear projectors of this kind are known from the German DE 43 24 849 C2. The deflecting mirror known from this reference is intended to reduce the construction depth. The reasoning behind this is as follows: Due to the laws governing geometrical optics, a determined optical path is predetermined by the image size. Particularly in a rear projector according to DE 43 29 849 C2, image generation relies on angular deflections of light bundles. Therefore, a magnification of the image is always tied to an increase in the dimensions of the device. This means that the construction depth that can be achieved is always limited for a given image size.
In order to provide small housing depths, that is, the flattest rear projectors possible, the optical beam path is folded via the deflecting mirror. While only one deflecting mirror is used for this purpose in accordance with the reference cited above, devices are also known from DE 31 52 020 A1 and U.S. Pat. No. 4,003,080 in which three deflecting mirrors are used.